Channel-to-channel adapters have been used for many years as a general purpose communication mechanism between computer systems. For example, channel-to-channel adapters have been the principal mechanism for connecting an S/390 system (offered by International Business Machines Corporation) to other heterogenous environments, such as IBM's RS/6000 and/or AS/400 systems. The channel-to-channel adapter is protocol independent, and has wide application in areas such as coupling of multiprocessor systems as well as in traditional communications protocol stacks (e.g., TCP/IP, SNA). Conventionally, the CTC function is implemented on a stand-alone piece of hardware.
For parallel channel interfaces, the CTC function is implemented in a separate box outside of, e.g., a Central Electronic Complex (CEC) (offered by International Business Machines Corporation). In IBM Enterprise System Connection Architecture (ESCON), the CTC function is refined so that any particular ESCON channel can be configured as a dedicated channel or a dedicated CTC, through different loads of microcode. For example, reference an IBM publication entitled “Enterprise Systems Architecture/390 ESCON Channel-To-Channel Adapter,” Publication No. SA22-7203-00 (1996). In all cases, the “entity” which provides the CTC function is dedicated to that purpose alone. Unfortunately, significant customer effort and expense is required for CTC configuration using such a dedicated CTC channel approach. Further, if a customer desires CTC communication between two logical partitions (LPARs), at least two channel path IDs (CHPIDs) are required. In view of the above, a need continues to exist for an enhanced approach to providing CTC functionality within a computing environment to better facilitate communication between computer systems.